Hermetic compressors having vertical crankshafts



March 2, 1965 w AYLlNG 3,171,588

HERMETIC COMPRESSORS HAVING VERTICAL CRANKSHAFTS Filed May 22, 1962 3Sheets-Sheet 1 March 2, 1965 R. w. AYLING 3,171,588

HERMETIC COMPRESSORS HAVING VERTICAL CRANKSHAF'TS Filed May 22, 1962 5Sheets-Sheet 2 Invenio'r: Rain-2 2 wflywag,

March 2, 1965 R. w. AYLING HERMEIIC COMPRESSORS HAVING VERTICALCRANKSHAFTS Filed May 22, 1962 3 Sheets-Sheet 3 United States Patent Oiiice A 3,l7l,5 88 Patented Mar. 2, 1965 3,171,588 HERMETIC COMPRESSGRSHAVING VERTICAL CRANKSHAFTS Robert W. Ayling, Staunton, Va., assignor toWestinghouse Electric Corporation, East Pittsburgh, Pa., a corporationof Pennsylvania Filed May 22, 1962, Ser. No. 196,821 3 Claims. (Cl.23tl206) This invention relates to refrigerant compressors, and relatesmore particularly to refrigerant compressors having verticalcrankshafts.

A refrigerant compressor which pumps a refrigerant that is miscible withits lubricating oil can be damaged on start up after the refrigerant hasmigrated to its crankcase during a period when the compressor is notoperating, and the refrigerant has flooded the crankcase. The floodingof the crankcase also results in start up noise, and in excessivestarting power requirements.

An object of this invention is to reduce the flooding of the crankcaseof a refrigerant compressor during its off periods.

This invention will now be described with reference to the annexeddrawings, of which:

FIG. 1 is a side view, partially in section, of a four cylinderrefrigerant compressor embodying this invention;

FIG. 2 is a side view partially in section, of another four cylinderrefrigerant compressor embodying this invention, and

FIG. 3 is a section along the lines 3-3 of FIG. 2.

Description FIG. 1

An upper shell it is welded to a lower shell 12, the latter having anoil sump 13 in its lower portion, the housing so formed being known as ahermetic one. An electric motor 8 having a cover 14, has a rotor 9attached to a vertically extending crankshaft 15 which has throws 16 and17 connected to piston rods 18 and'19 respectively, of pistons 21 and2t! respectively, in compressor cylinders 23 and 22 respectively. Thecover 14 is attached by a strap 24 and coiled spring 43 to the shell 12,the spring 43 and a similar spring which is not shown, behind the cover14, opposing the rotational torque of the motor. The cylinders 22 and 23are cast integral with an inner shell 25, and have heads 26 and 27respectively, which contain the usual suction and discharge valves whichare not shown. Discharge tubes 23 and 29 are connected to the cylinderheads 26 and 27 respectively, and to outlet tube 37. Formed to thecylinders above the latter is a bearing housing 3t containingspacedapart bearin s 31 around the shaft 15 between the motor 8 and thecylinders 22 and 23. The bearings 31 have a passage 42 therebetweenwhich opens into a passage 43 connecting with crankcase compartment 24.Joined to the cylinders below the latter and which forms the lowerportion of the inner shell 25, is a sleeve 35, to the lower portion ofwhich is attached another bearing housing 32 containing a bearing 33around the lower end of the shaft 15.

The lower end of the housing 32 is cylindrical and has therearound theupper portion of a coiled spring 34, the lower portion of which rests ina pan 36 on the bottom of the shell 12. Between the centers of the topsof the motor cover 14 and the shell 1% there is another coiled spring33. The springs 34 and 38 resiliently support the motor-compressor unitwithin the hermetic casing consisting of the shells and 12. Suction gastube 40 extends through the shell it for supplying suction gas to coolthe motor 8 as is usual in hermetic units. Suction ports 39 connect thesuction valves of the compressor cylinders with the space around themotor.

The numeral 41 indicates the normal oil level in the sump 13. The pan 34immersed in the oil has openings 44 for facilitating the entrance of oilinto the pan. The lower end of the shaft 15 restson a thrust Washer 45,the lower edge of which is seated on a shoulder 46 on the housing 32near its bottom, and has a central opening 47 extending therethrough.The bottom of the shaft has a central bore 51) connecting with theopening 47 and connecting with a radial bore 51 which opens into aclearance opening 52 within the housing 32 below the lower end of thebearing 33. A vertically extending, off center bore 55 within the shaft15 has its lower end opening into the bore 51, and near-its upper endopens into the lower end of a slanted bore 56, the upper end of whichextends through the side of the shaft opposite the bore 55, into thespace around the shaft. A groove 57 in the shaft 15 connects the bore 56with the upper hearing 31. A radial bore 58 connects the bore 55 withthe lower bearing 31. A radial bore 58 connects the bore 55 with thebearing 35.

The radial bore 51 acts as a centrifugal pump supplying oil from aroundthe bottom of the thrust washer 45 through the bore 55 to the bearings33 and 31. The oil at the top of the bore 55 cannot because ofcentrifugal force be thrown out through the slanted bore 56, but any gasmixed with the oil does pass out the slanted bore 56. The bearinghousing 32, the sleeve 35, the cylinders of the compressor and. thebearing housing 39 together form a partition enclosing the crankcasecompartment 24 and separating the latter from the motor 8 and the oilsump 13.

A tube so has a horizontally extending lower portion which extendsthrough the sleeve into the crankcase compartment 24, and has avertically extending upper portion with an open top 62 which is abovethe axes of the cylinders of the compressor, and above the level 63 ofmixed oil and refrigerant which is the highest level it would reachduring shut down.

Operation of FIG. 1

in operation, suction gas from an associated evaporator which is notshown, passes through the tube into the space around the motor 3 andpasses over the latter for cooling it. The suction gas then passesthrough the suction ports 39 and the associated suction valves into thecompressor cylinders 22 and 23 where it is compressed by the pistons 21and 22 respectively, and passes through associated discharge valves intothe tubes 28 and 29 and into the discharge tube 37.

Oil from the crankcase sump is drawn through the opening 47 in thethrust washer into the central bore St) in the bottom of the crankshaftand into the radial bore 51 which forms a centrifugal pump. The oil ispumped into the eccentric bore and from the latter through the radialbore 59 into the lower bearing 3-3, and from the bores 56 and 58 intothe bearings 31. Gas which enters the bore 55 passes out the slantedbore 56. Gas blowby past the pistons Ztl and 21 produces pressure in thecrankcase compartment 24. The gas blowby past the pistons in normaloperation tends to blow any oil leaking into the crankcase compartmentfrom the latter through the tube 68 into the sump 13. At shutdown, oilor the oil-refrigerant mixture is prevented from entering the crankcasecompartment since its only vent passage is the tube till, the upper endof which is located above the maximum level 63 which the oil-refrigerantmixture can reach.

Some liquid may enter the crankcase compartment through the lubricatingpassages and bearing clearances during a prolonged shutdown, butflooding is prevented or minimized.

Description of FIGS. 2 and 3 The embodiment of the invention of H65. 2and 3 is essentially the same as that of FIG. 1, the principaldifference being that instead of using an external tube to vent thecrankcase compartment, the vent passage is formed by a hole drilledthrough a boss cast on the inner shell around the crankcase compartment.

Referring now to FIGS. 2 and 3, since most of their components aresimilar to corresponding components of FIG. 1 they are given the samereference characters.

FIGS. 2 and 3 also differ from FIG. 1 in that FIG. 3 shows additionalcylinders 70 and 71 having heads 72 and 73 respectively, with FIG. 2showing the head 73; in that the discharge tubes 28 and 29 are shown onFIG. 2 as discharging into a manifold 74 to which the outlet tube 37 isconnected; the external vent tube 60 is not used; a boss 76 is cast aspart of the inner shell 25, and a vent passage 77 having an inlet withinthe crankcase compartment and having an outlet 78 above the axes of thecompressor cylinders and the maximum level 63 the mixed oil andrefrigerant can reach during shutdown. The vent passage 76 performs thesame function as the vent tube 60.

Another advantage of this invention is that when the compressor is usedas a heat pump compressor, when de frost of the associated outdoor coilis started, the sudden increase in suction pressure cannot drive the oilup into the running gear and cause noise as would otherwise occur.

What is claimed is:

1. In a refrigeration unit having a compressor with a verticallyextending crankshaft, upper and lower throws on said crankshaft, upperand lower cylinders having connecting rods connected to said upper andlower throws respectively, an electric motor above said cylinders havinga rotor connected to the upper portion of said crankshaft, an outershell around said motor and compressor and having its bottom spacedbelow the lower end of said crankshaft and forming an oil sump, a lowerbearing around the lower portion of said crankshaft, a bearing housingaround said bearing, an upper bearing around said crankshaft betweensaid motor and said cylinders, a

bearing housing around said upper bearing, an inner shell spacedinwardly of said outer shell and attached to said cylinders and saidmotor, said outer shell having a suction gas opening opposite saidmotor, the space between said inner and outer shells connecting with thespace between said outer shell and said motor, means including a passagewithin said crankshaft for pumping oil from said sump to said bearingsand for causing refrigerant vapor mixed with said oil to separate fromsaid oil and to flow outwardly from said passage into the space aroundsaid crankshaft, and means including said cylinders and said housingsforming a crankcase compartment around said throws and the lower portionof said crankshaft above said lower bearing, said compartment having avent opening below said lower. throw, the combination of a vent passagehaving its inlet connected to said opening and having its outlet in saidspace between said inner and outer shells above the axis of said lowercylinder.

2. The invention claimed in claim 1 in which said vent passage is atube.

3. The invention claimed in claim 1 in which said inner shell is acasting integral with said cylinders, and in which said vent passage isformed within said casting.

References Cited by the Examiner UNITED STATES PATENTS 2,048,025 7/36Philipp.

2,156,943 2/39 Heller 230206 X 2,228,364 1/41 Philipp 230-58 2,243,4665/41 Kucher 23058 X 2,738,919 3/56 Rusch et al 230206 X 2,898,072 8/59Buschmann 230-206 2,963,113 12/60 Ayling 230206 X 3,008,629 11/61Gerteis 230-206 X 3,021,995 2/62 Neubauer 230206 X LAURENCE V. EFNER,Primary Examiner.

JOSEPH H. BRANSON, JR., Examiner.

1. IN A REFRIGERATION UNIT HAVING A COMPRESSOR WITH A VERTICALLYEXTENDING CRANKSHAFT, UPPER AND LOWER THROWS ON SAID CRANKSHAFT, UPPERAND LOWER CYLINDERS HAVING CONNECTING RODS CONNECTED TO SAID UPPER ANDLOWER THROWS RESPECTIVELY, AN ELECTRIC MOTOR ABOVE SAID CYLINDERS HAVINGA ROTOR CONNECTED TO THE UPPER PORTION OF SAID CRANKSHAFT, AN OUTERSHELL AROUND SAID MOTOR AND COMPRESSOR AND HAVING ITS BOTTOM SPACEDBELOW THE LOWER END OF SAID CRANKSHAFT AND FORMING AN OIL SUMP, A LOWERBEARING AROUND THE LOWER PORTION OF SAID CRANKSHAFT, A BEARING HOUSINGAROUND SAID BEARING, AN UPPER BEARING AROUND SAID CRANKSHAFT BETWEENSAID MOTOR AND SAID CYLINDERS, A BEARING HOUSING AROUND SAID UPPERBEARING, AN INNER SHELL SPACED INWARDLY OF SAID OUTER SHELL AND ATTACHEDTO SAID CYLINDERS AND SAID MOTOR, SAID OUTER SHELL HAVING A SUCTION GASOPENING OPPOSITE SAID MOTOR, THE SPACE BETWEEN SAID INNER AND OUTERSHELLS CONNECTING WITH THE SPACE BETWEEN SAID OUTER SHELL AND SAIDMOTOR, MEANS INCLUDING A PASSAGE WITHIN SAID CRANKSHAFT FOR PUMPING OILFROM SAID SUMP TO SAID BEARINGS AND FOR CAUSING REFRIGERANT VAPOR MIXEDWITH SAID OIL TO SEPARATE FROM SAID OIL AND TO FLOW OUTWARDLY FROM SAIDPASSAGE INTO THE SPACE AROUND SAID CRANKSHAFT, AND MEANS INCLUDING SAIDCYLINDERS AND SAID HOUSING FORMING A CRANKCASE COMPARTMENT AROUND SAIDTHROWS AND THE LOWER PORTION OF SAID CRANKSHAFT ABOVE SAID LOWERBEARING, SAID COMPARTMENT HAVING A VENT OPENING BELOW SAID LOWER THROW,THE COMBINATION OF A VENT PASSAGE HAVING ITS INLET CONNECTED TO SAIDOPENING AND HAVING ITS OUTLET IN SAID SPACE BETWEEN SAID INNER AND OUTERSHELLS ABOVE THE AXIS OF SAID LOWER CYLINDER.